Abstract: Various embodiments of the present invention are generally directed to using a transducer to transfer data during a transducer displacement operation at a time during such operation when the transducer is substantially stationary.

Abstract: A processor is configured to perform a method (110) including a step of deriving lateral offset indicators (1062) from a longitudinal position measurement (130). Improved seek cost indicators (1063) are generated, some or all based on a respective lateral offset indicator (140). Then a target destination is selected using at least one of the improved seek cost indicators (150,160).

Abstract: Various embodiments of the present invention are generally directed to using a transducer to transfer data during a transducer displacement operation at a time during such operation when the transducer is substantially stationary.

Abstract: An apparatus and method for compensation for variation in timing skew in a disc drive having at least one rotating disc is provided. A first head is positioned over a first disc surface and a second head is positioned over a second disc surface. The first disc surface includes a track having a first plurality of sectors and the second disc surface includes a track having a second plurality of sectors. Each sector of the second plurality of the sectors corresponds to a different sector of the first plurality of sectors, thereby forming a plurality of pairs of corresponding sectors. A timing skew value for each pair of corresponding sectors is computed to obtain a sequence of timing skew values. Data related to the sequence of timing skew values is utilized to compensate for variation in timing skew.

Abstract: Method and apparatus for certifying servo sectors on recording surfaces of a disc stack of a data storage device to promote servo sector alignment among the various recording surfaces. A reference servo sector pattern is written to a first recording surface, the reference pattern comprising a plurality of angularly spaced apart servo sectors. Multiple interleaved sets of servo sector patterns are written to each of the remaining recording surfaces, each interleaved pattern respectively comprising a plurality of angularly spaced apart servo sectors. A selected interleaved pattern is identified from each of the remaining surfaces that provides a desired alignment with the reference servo sector pattern, and the non-selected servo sector patterns are overwritten. The servo patterns can be written to the discs prior to installation using a multiple disc writing (MDW) station, or after installation of the discs into the data storage device using a servo track writing (STW) station.

Abstract: A data storage system and a method for storing data in a data storage system are provided. The data storage system includes a data storage medium that has at least one physical track that stores at least a portion of manufacturing process data, and virtual tracks that store user data.

Abstract: The present invention recognizes that induced RRO is coherent, i.e., the RRO has a large degree of repeatability from track to track. The present invention is a zero acceleration profile (compensation) process that targets CRRO (Coherent RRO). A process of the present invention represents a considerable reduction in the factory calibration time compared to other compensation techniques currently used. The reduction in time is attributed to the fact that CRRO can be computed by averaging position error signals (PES) over multiple tracks as opposed to total RRO which is computed by averaging over multiple revolutions on the same track.

Abstract: An apparatus and method of tracking repeatable runout in a disc drive servo loop is provided in which a feedforward signal having harmonic components that are updated at a sample rate that is a fraction of a servo sector sample rate is employed during track following.

Abstract: Problems inherent in guiding a sensor via a piecewise-linear lateral parametric profile are generally avoided using at least one broadly curved, generally lateral profile (494). A sensor is configured to move in a nominally longitudinal direction relative to a frame of reference (110). A position scale is defined in a generally lateral direction relative to the longitudinal motion (115). Each broadly curved lateral profile is defined in terms of its corresponding position scale, the scale(s) and the profile(s) both being part of a parametric model that is available for use in guiding the sensor (145).

Abstract: Method and apparatus for more accurate track following. Control circuitry rotates a data storage surface containing thousands of annular tracks. A “measured” subset of the tracks is selected so as to be interspersed with an “unmeasured” subset. The calibration profile is derived based on position error signals each obtained by reading from the measured subset and not from the unmeasured subset. Data from the unmeasured subset of tracks is ignored, in generating and/or updating the profile.

Abstract: Problems inherent in guiding a sensor via a piecewise-linear lateral parametric profile are generally avoided using at least one broadly curved, generally lateral profile (494). A sensor is configured to move in a nominally longitudinal direction relative to a frame of reference (110). A position scale is defined in a generally lateral direction relative to the longitudinal motion (115). Each broadly curved lateral profile is defined in terms of its corresponding position scale, the scale(s) and the profile(s) both being part of a parametric model that is available for use in guiding the sensor (145).

Abstract: Method and apparatus for certifying servo sectors on recording surfaces of a disc stack of a data storage device to promote servo sector alignment among the various recording surfaces. A reference servo sector pattern is written to a first recording surface, the reference pattern comprising a plurality of angularly spaced apart servo sectors. Multiple interleaved sets of servo sector patterns are written to each of the remaining recording surfaces, each interleaved pattern respectively comprising a plurality of angularly spaced apart servo sectors. A selected interleaved pattern is identified from each of the remaining surfaces that provides a desired alignment with the reference servo sector pattern, and the non-selected servo sector patterns are overwritten. The servo patterns can be written to the discs prior to installation using a multiple disc writing (MDW) station, or after installation of the discs into the data storage device using a servo track writing (STW) station.

Abstract: A processor is configured to perform a method (110) including a step of deriving lateral offset indicators (1062) from a longitudinal position measurement (130). Improved seek cost indicators (1063) are generated, some or all based on a respective lateral offset indicator (140). Then a target destination is selected using at least one of the improved seek cost indicators (150,160).

Abstract: An apparatus and method for compensation for variation in timing skew in a disc drive having at least one rotating disc is provided. A first head is positioned over a first disc surface and a second head is positioned over a second disc surface. The first disc surface includes a track having a first plurality of sectors and the second disc surface includes a track having a second plurality of sectors. Each sector of the second plurality of the sectors corresponds to a different sector of the first plurality of sectors, thereby forming a plurality of pairs of corresponding sectors. A timing skew value for each pair of corresponding sectors is computed to obtain a sequence of timing skew values. Data related to the sequence of timing skew values is utilized to compensate for variation in timing skew.

Abstract: Method and apparatus for more accurate track following. Control circuitry rotates a data storage surface containing thousands of annular tracks. A “measured” subset of the tracks is selected so as to be interspersed with an “unmeasured” subset. The calibration profile is derived based on position error signals each obtained by reading from the measured subset and not from the unmeasured subset. Data from the unmeasured subset of tracks is ignored, in generating and/or updating the profile.

Abstract: The present invention recognizes that induced RRO is coherent, i.e., the RRO has a large degree of repeatability from track to track. The present invention is a zero acceleration profile (compensation) process that targets CRRO (Coherent RRO). A process of the present invention represents a considerable reduction in the factory calibration time compared to other compensation techniques currently used. The reduction in time is attributed to the fact that CRRO can be computed by averaging position error signals (PES) over multiple tracks as opposed to total RRO which is computed by averaging over multiple revolutions on the same track.